How To Start a Car With a Low Battery Charge?

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Car mechanic using battery jumper cables to start up a car with a low charge dead battery

A low battery will stop you from leaving the house in the morning or prevent you from getting back home at the end of the day. In an effort to avoid getting stranded somewhere, I want to help you start your car even though your battery is low. This is a common problem, so there are a number of potential solutions (thankfully). Take a look at this guide to get a quick answer to your question as I explain how you should start your car when your battery is low.

The best option is to jump-start your car. This directs additional energy into your battery, giving you enough juice to finally start your car. Other options include a rolling start, starting in neutral, and warming up your battery on especially cold days. You should also test the health of your battery and alternator, and look for damage on your battery’s terminals.

What the Battery Does

The battery is the heart of your car. When you turn on your car’s heater and hot air comes out, it’s thanks to the battery.

Any onboard electronic device gets its power from your car’s battery. Even when you charge your phone by plugging it into your car, it’s ultimately coming from the battery.

The battery can supply energy, but it can also receive it and recharge. This is done with an alternator. The alternator is a little engine that spins and generates energy before giving it back to the battery.

How a car battery charges the engine starting system and alternator

One of the more important functions of your car’s battery is starting your car. If you disconnect your battery, the car will never start. If the battery is too low, the car also won’t start.

As long as your car is running, the alternator is doing its job. As you drive and put a load on your engine, the alternator can create even more energy. It’s constantly recharging your battery.

This is an important concept because you don’t plug your car into a wall outlet at the end of the day. Your car sits in your garage until you start it again the next day.

This guide is specifically about low batteries, but you should also take a look at your alternator. If it’s faulty, then your battery won’t be able to recharge, and you’ll think it’s the battery’s fault. Replacing the alternator can bring your battery back to life.

Low vs Dead Battery

When your phone’s battery gets low, it still works. So, why is your car refusing to work with a low battery?

A car uses a lot of energy when it first starts. Energizing the starter engine and turning on all the onboard electronics takes a quick toll on a battery.

Car battery recharging

In this case, the battery is more comparable to a flashlight, not a phone. When a flashlight’s battery is low, the light will be dimmer and might even flicker. Your car needs a certain surge of energy to start the vehicle.

A low battery will suffer the same fate as a dead battery, in this case — your car won’t start until you fix the battery issue.

Pro Tip: Test the Life of Your Battery

There are 8 ways to tell if your battery is dead or dying. To find out the exact life of your battery, you can buy a dedicated tool. It checks the voltage and the response of your alternator.

If you use a tool like the one from KONNWEI, it’s pretty easy. The tool tells you the status of your battery and alternator.

KONNWEI KW208 12V Car Battery Tester

KONNWEI KW208 12V Car Battery Tester, 100-2000 CCA Load Tester Analyzer for Car Truck Marine Motorcycle SUV Boat
KONNWEI KW208 12V Car Battery Tester, 100-2000 CCA Load Tester Analyzer for Car Truck Marine Motorcycle SUV Boat

If the battery life is low, then you should swap out your battery as soon as possible. If the alternator is faulty, then forget about your battery for now and work on the alternator.

Doing a test like this is the only way to know what’s causing the problem and how to fix it.

For example, if your alternator is dead, changing your car’s battery won’t help at all. I’ve personally fallen into that trap a few times in the past when I was a young and naïve driver. Three dead batteries within a month later, and I realized there had to be something else wrong.

Ways to Start Your Car When The Battery Charge Is Low

Even when your battery isn’t dead, you can still run into problems. These ways will help you start your car when your battery is low.

Check the Battery Connection

The first thing to do is to check for looseness. This is more common than you might think.

Close up of the positive 12v volt battery terminals of the car vehicle

If your battery isn’t correctly plugged in, it will act like a battery that’s low. Push firmly on the two connections to ensure they’re in position.

Look For Corrosion

At the same time, you should also check for corrosion. Any amount of rust or liquid on the top of your battery is a big problem.

Close up of a car battery terminal corrosion

Corrosion could be a sign of a leaking battery. It could also be the byproduct of an older battery in a car that wasn’t stored properly.

In either case, use an anti-rust solution and wipe off the corrosion. You can try starting your car again, but I suggest that you check for corrosion again in the near future to make sure it isn’t a sign of a bigger problem.

Use a Car Battery Blanket

If you’re reading this in the winter, then your battery could be struggling because it’s cold. A lot of cars struggle to start in the cold, so you’re not alone.

This happens because your car’s battery relies on a chemical reaction. When temperatures drop, the reaction slows down. If your battery life is low, then this slowed reaction could result in your battery not working hard enough to start your car.

AOPEC Battery Insulation Kit

AOPEC Battery Insulation Kit - Fits Most Top And Side Mount Batteries, 40in. x 7in.
AOPEC Battery Insulation Kit – Fits Most Top And Side Mount Batteries, 40in. x 7in.

To heat things up, you can buy a specialized battery blanket. This wraps around your battery and plugs into the wall (or an extension cord).

Wires inside the blanket heat up, warming your battery. After enough time, your battery’s internal temperature will rise and your car will finally start.

Use a Makeshift Heat Lamp

If you don’t have immediate access to a battery blanket, you can make your own heat lamp. If your garage has a standing floor lamp, you have everything that you need. I use one of these lamps for working on my car, and they generate a lot of heat over time.

Makeshift red physiotheraphy heat lamp close up bulb

Simply position the lamp so that it’s taller than your car’s hood. Angle it down and focus its light on the battery. The lamp will get hot which will warm up your battery, achieving the same results as the battery blanket.

Try Starting in Neutral

In some cars, you can use a simple trick to get your car started. Instead of having your car in Park (or in First/ Reverse for a manual car), start in Neutral. This overrides a few safety switches which might solve your problem.

Putting the transmission gear stick lever into N neutral position inside the car interior

Push Your Car

If you have access to an able-bodied friend or two, you can give your car a little push to start. Literally. This tends to only work with automatic cars.

Have your friends stand behind your vehicle. Turn your key to the “on” position without fully starting the car. Engage the parking brake, shift into second, hold the clutch down until I say to release it, and then push the brake while releasing the parking brake.

Man pushing a broken down pickup truck in order to start it

Have your friends push as you release the brake. Wait until your car gets to about 5 mph, then quickly pop the clutch.

This should work but might take a few tries or a higher speed. When the car starts, it’s going to sound aggressive. It might involve backfiring, sputtering, and plenty of bucking.

Jump Your Car

Personally, the best option on this list is to go with a traditional jump-start. If you don’t know, this is when you siphon some energy from a healthy battery into your dying battery.

This is a safe process for every car involved, as long as you do it correctly. In other words, you aren’t going to take all the power out of your friend’s car’s battery, leaving them in the same situation you’re currently in.

A person jump starting the vehicle by using battery jumper cables and power from another vehicle to jump start the car with a low charge battery

To jump your car, follow my quick guide here.

After the jump, you should idle your car for a few minutes. I would suggest testing the life of your battery and understanding if there’s another problem, like a broken alternator. A jump-start might not fix the problem forever, but it will let you go to a mechanic or get home safely.

Use a Self-Jumper

If you don’t have access to a donor car to give you juice, you can use a self-jumper. This is one of my favorite products that I own.

I’ve tried a few different versions, and the NOCO Boost X seems to be the best on the market for its price. You can leave it in your trunk and charge it in your house occasionally to make sure it has enough battery life.

NOCO Boost X GBX45 1250A 12V UltraSafe Portable Lithium Jump Starter, Car Battery Booster Pack, USB-C Powerbank Charger, And Jumper Cables For Up To 6.5-Liter Gas And 4.0-Liter Diesel Engines
NOCO Boost X GBX45 1250A 12V

It is basically a miniature car battery that you can take around with you. It comes with jumping cables. Attach the self-jumper to your car and the device will jump-start your car without the need for a second car.

Prevent Your Battery from Dying in the Future

When the temperature drops, it’s easier for your car’s battery to die. I put together another guide that gives you 11 tips to keep your battery alive in the cold weather. I would suggest giving that a quick read so that you don’t have to worry about this problem as the months get even colder.

Conclusion

At this point, your car should be up and running again. I hope that this guide helped you start your car. If you have more car problems, take a look at the troubleshooting guides on my site. In addition, I have a list of products that can help you improve your car-owning experience.

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Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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